E. Hogenauer, "An economical class of digital filters for decimation and interpolation", IEEE Trans. Acoustics, Speech and Signal Processing 29, 2 (1981) 155--162.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....first few stages of a multirate filter resulting in relatively large transition bands. In other words: the stop bands are very narrow. Hence, comb filters are sufficient to attenuate these narrow stop bands. A well known class of comb filters are cascaded integrator comb filters (CIC fil ters) [12]. These filters implement the transfer function M 1 z i 1 z M 1 z 1 (33) without the need of multipliers. M is the sample rate reduction factor and R is called the order of the CIC filter. Solely adders, subtracters, and registers are needed. Hogenauer [12] states that ....

....(CIC fil ters) 12] These filters implement the transfer function M 1 z i 1 z M 1 z 1 (33) without the need of multipliers. M is the sample rate reduction factor and R is called the order of the CIC filter. Solely adders, subtracters, and registers are needed. Hogenauer [12] states that these filters generally perform sufficiently for decimating down to 4 times of the Nyquist rate. The ultimate goal is a multirate filter that requires multipliers only in the last stage at the lowest sample rate. For further reading on multirate filtering the reader is referred to ....

E. B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation," IEEE Transactions on Acoustics, Speech and Signal Processing, vol. ASSP-29, pp. 155--162, Apr. 1981.

.... WITH PREVIOUS WORK In the IIR FIR structure, shown in Fig.l(b) the FIR fil ter, 1 z ) k, operates at a sampling frequency M times lower than the IIR filter, In order to avoid reg ister overflow in the IIR filter, the wordlength of the IIR filter has to be equal to (Wo k log2M) bits [7], where W0 is the number of bits at the filter input. The major drawback of this architecture is that the IIR filter is operating at maximum sampling frequency and with a very large wordlength. Equation (1) can be written in the following form: log2M) i H(z) H (1 z 2 ) 2) Applying ....

E.B. Hogenauer, "An economical class of digital filters for dec- imation and interpolation," IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-29, no. 2, pp. 155162, Apr. 1981.

....widely used in the decimation filter of A D converters. These filters are usually implemented using the IIR FIR technique [Dijkstra88] Although the output of a modulator is coded on a very small number of bits, the wordlength of the IIR filter has to be large to avoid any register overflow [Hogenauer81]. The major drawback of this architecture is that the IIR filter is operating at maximum sampling frequency and with a large wordlength. This considerably increases the power consumption of Comb filters [Aboushady97] Barrett97] Recently, lower power consumption has been achieved using the FIR2 ....

....respectively. In the IIR FIR structure, shown in Fig.9.1(b) the FIR filter, 8. operates at a sampling frequency times lower than the IIR filter, In order to avoid register overflow in the IIR filter, the word length of the IIR filter has to be equal to bits [Hogenauer81], 9 is the number of bits at the filter input. The major drawback of this architecture is that the IIR filter is operating at maximum sampling frequency and with a very large word length. Equation (9.1) can be written in the following form: 9.2) Applying the commutative rule ....

E. B. Hogenauer. An economical class of digital filters for decimation and interpolation. IEEE Transactions on Acoustics, Speech, and Signal Processing, ASSP29 (2):155--162, April 1981.

....the Z transform of h #k#T # (see eq. 10) H PF #z# L# H#z# s#k#T # Figure 2: Increasing the sample rate by an integer factor L Calculating the frequency response of the sampled Bsplines unveils a very interesting connection to the very simple CIC filters (for details on CIC filters see [6]) The fourier transform of a continuous time B spline of degree #N # 1# is # # f ##### #t###T#sinc# fT## (16) with sinc#x##sin##x# ##x#.Since # #f#is not band limited, sampling the B spline causes aliasing. Hence, the frequency response of the sampled B spline h B spline #k ....

.... ) 7] The filter H CIC### # H # ## is a simple running N G 2 1 # 8 # 6 # 384 # 120 Table 2: Transfer function of the FIR filter G sum filter (causal notation) CIC #z### L#1 # n#0 #n #L (20) mostly implemented as the well known CIC filter [6]. Hence, the implementation of a spline interpolator can be realized very efficiently (see fig. 3) The combination of the B spline with the pre filter is called cardinal spline. Since the pre filter is a symmetric IIR filter, the cardinal spline has infinite support (duration) Therefore there ....

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Eugene B. Hogenauer. An Economical Class of Digital Filters for Decimation and Interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, ASSP-29(2):155--162, April 1981.

....criterion for aliasing free signals. A rate change by an arbitrary rational factor L M can be accomplished by up sampling by L, antiimage filtering, anti aliasing filtering and finally downsampling by M. An efficient method for performing the necessary filtering has been proposed by Hogenauer in [3]. The described CIC filters (cascaded integrator comb) are time varying recursive FIRfilters. Conventional FIR filters are usually applied for finalizing the adaptation process. One can realize that the structure equals the structure of the noise shaper allowing a combination of both resulting in ....

Hogenauer, E. B.: An Economical Class of Digital Filters for Decimation and Interpolation, IEEE Trans. ASSP, April 1981, 155162.

....DSP can realize all necessary multipliers in a time shared manner. Another class of simplified structures for integer factor SRC results from sensible factorizations of the transfer function of certain filter types. These are cascaded comb filters [10] and cascaded integrator comb (CIC) filters [11]. Especially, the latter have enjoyed great success and wide application. They are multiplierless comb filters with low effort. Due to the small width of their stop bands they should be applied at high OSRs of the channel of interest. Their simple structure supports an implementation at Finally, ....

E. B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation," IEEE Trans. Acoustics, Speech and Sig. Proc., vol. ASSP-29, no. 2, Apr. 1981, pp. 155--62.

....Hentschel, Gerhard Fettweis Dresden University of Technology Mobile Communications Systems Chair D 01062 Dresden Germany e mail: henker ifn.et. tu dresden.de ABSTRACT Sample rate conversion (SRC) with rational factors can be realized by interpolation followed by decimation, where CIC Filters [1] can be chosen for either. However, the necessary increase of the sample rate that goes with the interpolation is not feasible in most RF applications. Therefore a time variant implementation of CIC filters is presented which circumvents the high intermediate sample rate. This time variant ....

....increasing the input sample rate due to interpolation (see fig. 1) is not feasible. In the following we show that in connection with CIC filters this can be avoided. 2. CIC FILTERS FOR INTERPOLATION AND DECIMATION CIC filters are linear phase FIR filters which have been thoroughly discussed in [1]. For completeness their structure is given in fig. 2. The CIC filter realizes a moving average calculation of the order N. The frequency response of the filter is H(F) K sin(pRF) sin(pF) O (R 1)NF (1) with 0 F = fT 1andR=KL or KM, K OE 1,2 Hence it suppresses aliasing or imaging ....

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Eugene B. Hogenauer. An Economical Class of Digital Filters for Decimation and Interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, ASSP29 (2):155--162, April 1981.

....fulfilling the constraints of the current application. Such impulse responses can also be implemented on the Farrow structure, but require sophisticated controlling [13, 14] Finally, comb filters attenuating potential aliasing components implemented as cascaded integrator comb (CIC) filters [15] are suggested. These filters are highly efficient multiplier free filters for sample rate increase and decrease by integer factors. Combining both filters for up and downsampling yields a system performing rational factor SRC. The drawback of a cascade of interpolator and decimator is generally ....

E. B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation," IEEE Trans. Acoustics, Speech and Sig. Process., vol. ASSP-29, no. 2, Apr. 1981, pp. 155--62.

....In such systems it is necessary to convert between an oversampled rate and a processing rate, which could be the chip or symbol rate of a certain communications standard. Many solutions to integer factor SRC exist, among which polyphase filters [2] and CascadedIntegrator Comb Filters [3] play an important role. Fractional SRC is far more demanding than integer factor SRC. This is where interpolation is commonly regarded the very solution. Still, as explained only the antialiasing constraint should be of interest when searching for and designing algorithms and systems for ....

Eugene B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation," IEEE Transactions on Acoustics, Speech and Signal Processing,vol. ASSP-29, no. 2, pp. 155--162, Apr. 1981.

....power consumption is an issue, e.g. mobile communications terminals, low complexity solutions are sought for. Comb filters having the property to mainly attenuate the aliasing (or imaging) components have been shown to have a very efficient realization called cascaded integrator comb (CIC) filters [2]. Besides the low complexity the main advantage of this realization is its independence from the rate change factor. Combining re sampling and filtering the number of notches of the transfer function is selected solely by choosing the desired rate change factor N . For reasons of completeness the ....

Eugene B. Hogenauer. An Economical Class of Digital Filters for Decimation and Interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, ASSP29 (2):155--162, April 1981.

....two s complement to signmagnitude representation, and up conversion of the signal in the GPS branch, and . Channelisation, up sampling, and Sigma Delta modulation of the signal in the GSM branch. For reasons of power consumption the filters for channelisation are implemented using CIC filters [Hog81] and multiplier free FIR filters (multi rate filter implementation) This is feasible, for mobile communications signals are to a certain degree immune to slight pass band ripple of the filters. Moreover, the characteristics of the decimation filter at the input of the GSM base band processor has ....

Hogenauer, E.B.: "An Economical Class of Digital Filters for Decimation and Interpolation", IEEE Trans. ASSP, Vol. 29, Apr. 1981, pp. 155-162 Fig. 1: System Architecture of GSM/GPS receiver

....before any decimation takes place. The power consumption of Comb filters is then very high. The transfer function H(z) of a Comb filter of order k and for a decimation ratio M is defined by H(z) 1 z M 1 z 1 k : 1) These filters are usually implemented using the IIRFIR technique [1][2] In this case, the Comb filter, which is actually an FIR filter, is decomposed into two filters: an IIR filter H 1 (z) 1= 1 z 1 ) k and an FIR filter H 2 (z) 1 z M ] k . Using the commutative rule [2] the second filter is transferred after decimation, Fig1(b) and then operates ....

....rule [2] the second filter is transferred after decimation, Fig1(b) and then operates at a much lower sampling frequency fs M . To ensure stability, the minimum wordlength at the input of the IIR filter is fixed to (B in k log 2 M) bits, where B in is the number of bits at the input [1]. The major drawback of this architecture is that the IIR filter is operating at maximum sampling frequency f s and with a large wordlength. This increases drastically power consumption and limits the highest operating frequency of the decimation filter. Equation (1) can be written in the ....

E. B. Hogenauer. "An Economical Class of Digital Filters for Decimation and Interpolation". IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-29(No. 2):155--162, April 1981.

....of the proposed structure are improved, especially the worst case aliasing attenuation level. 2. BUILDING UNITS Cascaded integrator comb (CIC) filters are commonly used for decimation and interpolation by integer ratio providing efficient anti image and anti alias filtering [3]. These filters have a simple regular structure without multipliers. CIC decimation filter (see [3] consists of N cascaded digital integrator stages operating at high input data rate F in , followed by N cascaded comb or differentiator stages operating at low sampling rate F in R. Its ....

....level. 2. BUILDING UNITS Cascaded integrator comb (CIC) filters are commonly used for decimation and interpolation by integer ratio providing efficient anti image and anti alias filtering [3] These filters have a simple regular structure without multipliers. CIC decimation filter (see [3]) consists of N cascaded digital integrator stages operating at high input data rate F in , followed by N cascaded comb or differentiator stages operating at low sampling rate F in R. Its frequency response is given by ( 2 sin( 2 sin( 2 ) 1 ( N R N j CIC R R e e H # ....

E. B. Hogenauer, "An economical class of digital filters for decimation and interpolation," IEEE Trans. Acoust., Speech, Signal Processing, Vol. ASSP-29, pp. 155-162, April 1981.

....composed of a carrier numerically controlled oscillator (CNCO) and a phase rotator. The CNCO generates the rotation angle, while the phase rotator acts as a digital single sideband mixer. Programmable up sampler: The up sampler is a second order Cascaded Integrator Comb (CIC) interpolation filter [6], which supports sample rate conversion factors of powers of two, ranging from 1 to 256. Fixed Up Converter: This up converter translates the baseband spread spectrum signal to a fixed IF of one fourth of the DAC sampling frequency. This upconverter can be disabled. Pre Compensation Filter: This ....

Eugene B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation," IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-29, no. 2, pp. 155--162, Apr. 1981.

....high precision is RF to baseband conversion. An RF to baseband converter, sometimes called a channelizer, is a steep skirt high decimation rate filter which accepts data in the high MHz range and exports a lowfrequency baseband signal. Such systems are often architected as a Hogenauer CIC filters [5]. 3. THE HOGENAUER CIC FILTERS The Cascade Integrator Comb (CIC) a.k.a. Hogenauer filter) have proven to be an effective element in high decimation or interpolation systems. Examples of highly oversampled systems include channelizers and converters. Figure 1(a) shows a three stage CIC filter ....

....wordwidth of 8 bits, along with D = 2, R = 32, or DR = 2 Delta 32 = 64, would require an internal wordwidth of W = 8 3 log 2 (64) 26 bits to insure that run time overflow would not occur. The output wordwidth would normally be a value significantly less then W , 10 bits for example. Hogenauer [5] noted by careful analysis that some of the lower significant bits form early stages can be eliminated without sacrificing system integrity. Figure 2 shows (a) 26 bit 26 bit 26 bit 26 bit 26 bit 26 bit I I I D 1 z z C C C R 6 6 6 8 8 6 6 6 6 8 8 6 6 8 8 6 C C C I I I CRT e 10 bit ....

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E. B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation". IEEE Transactions on Acoustics, Speech, and Signal Processing, 29(2):155-162, April 1981.

....angle up to order six 3.6 5.7 All angle up to order six 2.8 4.7 All angle up to order eight 2.4 3.7 tion was found at a sampling frequency of 16624 Hz. An integer coefficient half band filter HB6 [10] anti aliasing filter and third order multiplier free CIC filter (a.k.a. Hogenauer filter [11]) was added to the design to suppress unwanted frequency components as shown in Figure 5. The bandwidth of each resonator can be independently tuned by the number of stages and the delays in the comb section. The number of stages and delay was optimized to meet the lis 8 16 24 32 40 48 56 64 72 ....

E. B. Hogenauer. An Economical Class of Digital Filters for Decimation and Interpolation. IEEE Transactions ASSP, pages 155--162, April 1981.

....symmetry to the unit cycle which results in linear phase and constant group delay properties. FSFs of this type are known to provide very efficient multi rate interpolation and decimation solutions and may serve as high decimation rate filters for RF to basebandconversion of radio signals [5, 6]. If the filter of Figure 2(a) is realized with a non recursive FIR, then D (complex) multiplications and D Gamma 1 additions are used. In contrast, the recursive design uses only one multiplication and one subtraction 2.1. Improvement of Frequency Selective Properties Using Algebraic Integers ....

....[10] it should be emphasized that the algebraic integer realization has higher complexity (four times as many comb sections) but has a single complex pole and is therefore a single passband filter and consequently does not need an additional anti aliasing filter. 3. CONCLUSION The Hogenauer [6] idea of cascade integrator comb filter was extended to bandpass filters. Using a digital signal processing scheme with algebraic integers provides single passbandfrequency sampling filter building blocks. These filters are of low complexity and are multiplier free, so that a wide selection of ....

E. B. Hogenauer, "An Economical Class of Digital Filters for Decimation and Interpolation". IEEE Transactions on Acoustics, Speech, and Signal Processing, 29(2):155-162, April 1981.

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E. Hogenauer, "An economical class of digital filters for decimation and interpolation", IEEE Trans. Acoustics, Speech and Signal Processing 29, 2 (1981) 155--162.

No context found.

E.B. Hogenauer. "An economical class of digital filters for decimation and interpolation". IEEE Trans. on Acoustics, Speech and Signal Processing, ASSP-29(2):155--162, April 1981.

No context found.

E. B. Hogenauer. An Economical Class of Digital Filters for Decimation and Interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, ASSP-29(2):155--162, Apr. 1981.

No context found.

E. Hogenauer. An economical class of digital filters for decimation and interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, 29(2):155--162, 1981.

No context found.

E. B. Hogenauer. An economical class of digital filters for decimation and interpolation. IEEE Transactions on Acoustics, Speech and Signal Processing, 29(2):155-162, 1981.

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Hogenauer, E. B.; An Economical Class of Digital Filters for Decimation and Interpolation; IEEE Trans.

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E. B. Hogenauer, "An economical class of digital filters for decimation and interpolation," IEEE Transactions on Acoustics, Speech and Signal Processing , pp. 155--162, Apr. 1981.

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E. B. Hogenauer, "An economical class of digital filters for decimation and interpolation," IEEE Transactions on Acoustics, Speech and Signal Processing 29, pp. 155--162, April 1981.

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